Abstract: The X65 pipeline steel 13MnNbTi (% ： 0. 10 ~Q 16C, 1.20 ~ 1.40Mn, 0. 03 ~0. 05Nb, 0.01 ~0. 02Ti, 0.025 ~0. 05Al) is pilot-produced by 120 t top and bottom combined blown converter-100 t LF (VD) -5 strands Φ300 mm round bloom casting flow sheet at steelmaking plant, Baotou Steel Union Co Ltd. Production practice shows that it is available by desulphurization of hot metal ([S] ≤0. 005% ) , using slag stopper during converter tapping, basicity of refining slag ≥3. 0, VD treatment ≥13 min, to get [S]≤0. 005% , [P] ≤0. 015% and [ H] ≤1.5 x 10^-6. With shielding casting in whole process and mold electromagnetic stirring, the oxygen content in steel is (13 ~21) x I0^-6, average oxygen content is 16. 44 x 10^-6, the surface quality of bloom is fine and the rating of macrostructure is 0 ~ 1.

Key words: X65 Pipeline Steel, 6300 mm Round Cast Bloom, Process Practice

摘要： 包钢钢联股份有限公司炼钢厂采用120 t顶底复吹转炉-100 t LF(VD)-5流Φ300 mm铸坯连铸工艺流程试生产X65管线钢13MnNbTi(%:0.10～0.16C、1.20～1.40Mn、0.03～0.05Nb、0.01～0.02Ti、0.025～0.05Al)。生产实践表明,通过铁水脱硫([S]≤0.005%),转炉挡渣出钢,精炼渣碱度≥3.0,VD处理≥13 min,可以使[S]≤0.005%、[P]≤0.015%、[H]≤1.5×10^-6。通过全程保护浇铸和结晶器电磁搅拌工艺,钢中氧含量(13～21)×10^-6,平均氧含量16.44×10^-6,铸坯表面质量良好,低倍组织0～1级。

关键词: X65级管线钢, Φ300 mm圆铸坯, 工艺实践